Rotary pump



June 11, 1929. T.l P. www@- 1,716,901

ROTARY PUMP Filed Aug. 2, 1927 'Patented Juney 11, 1929.

UNITED STATES PATENT OFFICE.

THOMAS P. ROCHFORD, OF SEATTLE, WASHINGTON, ASSIGNOR T .T. P. BRICKER ANI) W. A. BRICKER, BOTH OF SEATTLE, WASHINGTON.

ROTARY PUMP.

Application led August 2, 1927. Serial No. 210,029.

This invention relates to rotary pumps and its object is the perfecting of pumps of this character to provide a durable and strong construction which will be peculiarly v efficient and one which will operate with a minimum consumption of power.

The invention consists in the novel construction and adaptation of the pump casing, the pistons, the mounting thereof, and

other details claimed.

In the accompanying drawing,- Figure-1 is a view partly in side elevation and partly in section of a pump embodying the present invention, said section being taken substantially on line 1-1 of Fig. 2; Fig. 2 is a longitudinal section taken substantially in line 2-2 of Fig. 1; and Fig. 3 is a perspective View of one 4of the duplex pistons, shown detached, and partly broken away to illustrate the piston packing ring.

In said drawing, the reference numeral 5 represents the pump casing body having a chamber of a general elliptic form and is provided with removable heads G having in their peripheries rabbets 7 to afford central protruding portions which fit into recesses 8 provided in the respective ends of the body. 9 represents packing boxes provided upon the casing heads for a shaft 10 which xtends centrally through the casing cham- Keyed or otherwise secured to the shaft 10 is a rotor having acentral cylindrical drum portion 11 of a diameter to it within a bored portion centrally of the major axis of the said chamber and contacting with the peripheral surfaces 12 of said bored portion at diametrically opposite sides of the drum. Said drum occupying the bored central portion of the casing chamber provides cavities or pumpingchambers 13 at diametri'cally opposite sides of the drum.

Each of the pumping. chambers is provided With an arcuate outer surface 14.- concentric to the shaft axis, the ends of said arcuate surfaces being connected by surfaces 15 which are tangential with the respective bore surfaces 12.

lRigidly secured as by means of'bolts 1G to the ends of the drum 11 the rotor is provided With circular disks 17 4of a diameter somewhat greater than the major diameter of the casing chamber to provide circumferential flanges to extend into circulail rehereinafter described and cesses 18 provided in the casing as shown in Fig. 2.

The drum part 11 is provided with slots 19 formed to arcs of circles and arranged to extend laterally through such drum part with their convex sides innermost, as shown in Fig. 1. The Widths of the said slots 19, see Fig. 2, at their midlengths is less than the distance between the rotor disk elements 17, but near their ends, said slots, as at 191, alrel of Widths equal to the spacing of the c 1s rs.

Fitted to reciprocate laterally Within the' respective slots are blocks 20 o f substantially the shape of a capital letter H in horizontal section (Fig. 3) and in end elevation of a circular' arc corresponding to the arc of the respective drum slot. More particularly, the H-shape of a block provides a transverse central stem, indicated by 201, connecting transverse bar sections 202, one at each end of a block, constituting pistons and anentire block, including the stem and coupled pistons will be hereinafter termed a duplex piston. The Width of t-he pistons 202 is such as will make sliding fits With the respective disks. The Width of a stem is less than the Width of a slot at its midlength. In the extremities of a duplex piston the same are provided with grooves to accommodate, in each groove, a metal packing strip 21 and a spring 22 which functions to maintain the respective strips in continuous contact With the peripheral Wall of the casing chamber.

Provided at opposite sides of each groove and adjacent to the .circumference of the drum part 11 are recesses 23 for rollers 24 which are adapted to bear against the duplex pistons. Backing plates 25 of hard metal are desirably provided to take the Wear of the rollers.

The respective pumping chambers 13 are provided at their opposite sides with inlet and outlet ports 26 and 27 which communicate with liquid supply and discharge pipes 26l and 271 respectively.

In the construction of my improved pump the transverse formation of the casing chamber is such that the distances between portions of the peripheral surfaces thereof measured on the arc of thel respective drum slots 19 will be substantially equal for every rotary position of the rotor.

Eachof the -duplex pistons 20 (Fig. 3) is,

moreover, of a single piece-that is, the pistons 202 proper are integral with the respective stem 201-and its length is slightly less vthan the distance between portions of the 'above referred to peripheral surfaces of the easing chamber With respect to the drum slots.

of the inner peripheral surfaces ofthe casing and also serves to afford a practically non-leakable contact between the pistons and the casing.

In operation', the rotor is driven by power applied through the shaft 10 causing the pistons to be revolubly carried about the shaft axis and to traverse the pumping-chambers 13 between the respective liquid inlets 26 and Y outlets 27 thereby inducing the flow of the liquid into the pumping chambers and expelling it from the latter through the associated outlets.

The operation of the invention is simple and most effective, the pistons being protruded and retracted in vpassing into and from the respective pumping chambers by the camaction of the casing itself.

' What I claim is 1, Ina rotary pump, the combination with a casing having a body portion provided in each of its ends'with a circular'recess and an elliptical .chamber between the recesses, a re movable cover for ea'ch end of the casing body, and a shaft, extending centrally through said chamber and said circular recesses, of a rotor mounted upon said shaft- Within the casing, said r'otor comprising a cylindrical drum operating within said chamber and disk elements rotatable in the respective recesses, said drum being located The spring pressed packing strip-s 2f comv pensate for irregularities in the forma-tion' to divide said chamber into two pump compartments one at each end of the chamber at diametrically opposite sides of the drum, said drum having therein transversely arranged slots of a circular-are form, a curved member provided in each of saidslots and formed to provide piston elements at the opposite ends thereof, each of said piston elements having a groove, and spring-pressed packing strips in said grooves.

2. In a rotary pump, the combination with a casing having a body portion provided in each ot its ends with a elrcular recess andA an elliptical chamber between said recesses,

a removable cover for each end of the casing body, and a shaft extending centrally through said chamber and both of said recesses, of a 'rotor mounted upon said shaft' said piston elements having a groove, springpressed packing strips in said grooves, and anti-friction rollers for the respective piston elements provided at the convex and concave sides thereof in the drum portion of the rotor and inproximity to both ends of the respective slots. l

Signed at Seattle, Washington, this 8th day of July, 1927. i

THOMAS P. RocHFoRD. 

